In products which have a sticky or tacky material on a substrate web, where the sticky or tacky material is applied to or made on the substrate web and then during use is removed from the substrate web, there has been a problem in manufacturing the product on the substrate web. After the tacky material is deposited or made on the web substrate and when the web product is completed, it often is either stacked or rolled into a roll for shipment and later use. The sticky material should not stick to the underside of the web when it is stacked or rolled. The problem is particularly acute in the manufacture of roofing materials which include a layer of tacky bituminous material.
In known methods of manufacturing methods of roofing materials, bituminous material has been applied on a web which may be or forms a part of the release liner. The application of the bituminous material forms a bituminous layer on a release substrate or liner. The release liner comprises a paper layer, a barrier layer, and a release layer. The bituminous material is applied to and is in contact with the release layer of the substrate. Hence, the bituminous material can be released from the substrate when it is mounted on a roof. The bituminous layer generally has been covered with a plastic film layer in such a manner that only a narrow area at the both edges of the bituminous layer is uncovered. The web has been wider than the width of the bituminous layer. This permits the edges of the web to be folded or turned backwards to face the edge area of the bituminous material layer. The folded edges help alleviate the bituminous layer from sticking to other sheets of the same material which have been piled one on the other. The plastic film over the bituminous layer and folded edges also permit the bituminous covered web to be in a roll form with the edges of the of the bituminous layer being protected by the folded edges of the web. However, this kind of solution requires excess material and an excess stage in manufacturing where the edges are turned or folded over. Furthermore, the web product is difficult to handle when the release liner is detached at the release layer from the bituminous layer for application of the bituminous layer to a roof.